基于最小二乘离散状态空间的振级计算方法

Vibration Level Computation Based on Least Squares Discrete State Space System

在振级计算过程中,需按要求对加速度信号进行计权。最常见的计权方法是利用带通数字滤波器提取各个频程内的加速度信号并乘以对应的计权因子,在合适的滤波参数下,该方法具有良好的计算精度,但计算效率较低。针对此问题,提出一种基于状态空间的加速度计权方法。首先,采用最小二乘算法,将频率计权传递函数转换为单输入-单输出离散系统的状态空间矩阵;其次,将原始加速度信号作为该离散系统的输入,所得系统输出信号即为计权加速度;最后,通过仿真和实测算例验证了该方法的高效性和精确性。

It is an essential step to weigh the acceleration signal in the process of vibration level calculation.The most common weighting method is to use the band-pass digital filters to extract the acceleration data in the corresponding frequency range,and then multiply them by the corresponding weighting factors.Under appropriate filtering parameters,this method has a high computational accuracy but low computational efficiency.Therefore,a method based on least squares state space system is proposed to calculate weighted acceleration.Firstly,the least square algorithm is used to transform the transfer function of the principal weightings into the discrete state space of a single-input-single-output system.Then,the original acceleration signal is taken as the input of the discrete system,and the output signal of the system is the weighted acceleration.Finally,a simulation and a practical test case are applied to validate the accuracy and efficiency of the proposed method.The results show that the new method has a better precision and effectiveness.